Hybrid solar lighting distribution systems and components

ABSTRACT

A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part (CIP) of U.S. patentapplication Ser. No. 10/633,027 filed on Aug. 1, 2003, which is a CIP ofSer. No. 09/953,848 U.S. Pat. No. 6,603,069, entitled “Adaptive, FullSpectrum Solar Energy System”, filed on Sep. 18, 2001 and issued on Aug.5, 2003, both herein incorporated by reference in their entirety.

STATEMENT REGARDING FEDERAL SPONSORSHIP

This invention was made with Government support under contract no.DE-AC05-00OR22725 to UT-Battelle, LLC, awarded by the United StatesDepartment of Energy. The Government has certain rights in theinvention.

FIELD OF THE INVENTION

This invention relates to the field of solar energy systems and morespecifically to hybrid solar lighting distribution systems andcomponents for distributing visible light. Hybrid solar concentratorcollector(s) for capturing incident solar radiation and using portionsof the solar spectrum for visible lighting are also taught. The termsconcentrator, collector, and concentrator collector are usedinterchangeably in this specification. Visible lighting is distributedthrough a light distribution system.

BACKGROUND OF THE INVENTION

Throughout the 1900s, use of the sun as a source of energy has evolvedconsiderably. Early in the century, the sun was the primary source ofinterior light for buildings during the day. Eventually, however, thecost, convenience, and performance of electric lamps improved and thesun was displaced as our primary method of lighting building interiors.This, in turn, revolutionized the way we design buildings, particularlycommercial buildings, making them minimally dependent on naturaldaylight. As a result, lighting now represents the single largestconsumer of electricity in commercial buildings.

During and after the oil embargo of the 1970s, renewed interest in usingsolar energy emerged with advancements in daylighting systems, hot waterheaters, photovoltaics, etc. Today, daylighting approaches are designedto overcome earlier shortcomings related to glare, spatial and temporalvariability, difficulty of spatial control and excessive illuminance. Indoing so, however, they waste a significant portion of the visible lightthat is available by shading, attenuating, and or diffusing the dominantportion of daylight, i.e., direct sunlight which represents over 80% ofthe light reaching the earth on a typical day. Further, they do not usethe remaining half of energy resident in the solar spectrum (mainlyinfrared radiation between 0.7 and 1.8 μm), add to building heat gain,require significant architectural modifications, and are not easilyreconfigured. Previous attempts to use sunlight directly for interiorlighting via fresnel lens collectors, reflective light-pipes, andfiber-optic bundles have been plagued by significant losses in thecollection and distribution system, ineffective use of nonvisible solarradiation, and a lack of integration with collocated electric lightingsystems required to supplement solar lighting on cloudy days and atnight.

BRIEF SUMMARY OF THE INVENTION

This invention improves the total end-use power displacement efficiencyof solar energy by integrating solar technologies into multi-use hybridsystems that better utilize the entire solar energy spectrum. Asillustrated in FIG. 1, a primary mirror 30 concentrates the entire solarspectrum of incoming sunlight onto a secondary mirror 31 where thesunlight is reflected into a fiber receiver 32 for distribution to thefiberoptic lighting network. The reflected sunlight from the secondarymirror 31 is preferably filtered at the secondary mirror 31 surface suchthat only visible light is reflected onto the fiber receiver 32. Theprimary mirror 30 and secondary mirror 31 can be a single piece mirroror segmented into multiple sections for assembly. The secondary mirrorpreferably utilizes a cold mirror coating to efficiently separate theinfrared and visible portions of the spectrum. The “HeatBuster” coldmirror coating, developed by Deposition Sciences Inc., is a typical coldmirror coating that reflects UV and visible light while transmitting IR.Using a MicroDyn sputtering technique allows the coating to operate upto a maximum temperature of 500° C.

This hybrid solar lighting (HSL) solar energy system is a uniquealternative to solar energy use in buildings. It uses solar energy froma dynamic, systems-level perspective, integrates multiple interdependenttechnologies, and makes better use of the entire solar energy spectrumon a real-time basis.

The HSL system uses a hybrid solar concentrator that efficientlycollects, separates, and distributes the visible portion of sunlight.The optical and mechanical properties of improved large-core polymeroptical fiber light distribution system more efficiently deliver largequantities of visible sunlight into buildings. Once delivered, thevisible sunlight is used much more effectively than previously toilluminate building interiors using new hybrid luminaires.

This invention redirects and more efficiently uses portions of the solarenergy spectrum originating from a common two-axis, tracking solarconcentrator in real-time using electro-optic and or opto-mechanicaldevices. Analytical/experimental models and intelligent controlstrategies enhance the use of hybrid solar lighting systems in manyapplications including commercial buildings, display lighting,billboards, pools, spas, street lights, ships, and photobioreactorsusing either sunlight sources or man-made light sources.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the major components of the hybrid solar concentrator.

FIG. 2 is a front view of the hybrid solar collector.

FIG. 3 is a rear view of the hybrid solar collector.

FIG. 4 shows a cross section of the primary and secondary mirrors.

FIG. 5 is a rear view rendering of the hybrid solar collector.

FIG. 6 is a rendering of the fiber receiver mounted in the concentrator.

FIG. 7 shows the fiber receiver in both unassembled and assembledconfigurations.

FIG. 8 is a rendering of an indirect hybrid lighting embodiment.

FIG. 9 is a rendering of a recessed down-lighting hybrid lightingfixture embodiment with outboard fiber optic lighting.

FIG. 10 is a rendering of a track lighting hybrid fixture embodimentwith outboard fiber optic lighting.

FIG. 11 is a rendering of a hybrid solar white light LED luminaire.

DETAILED DESCRIPTION

In the hybrid solar lighting (HSL) system, the luminous efficacy offiltered sunlight is more than double its only competition (electriclamps). Therein lies the primary motivation for using filtered sunlightfor lighting purposes in buildings.

FIG. 1 illustrates a preferred embodiment of the hybrid solarconcentrator where a primary mirror 30 concentrates the entire solarspectrum of incoming sunlight onto a secondary mirror 31 where thesunlight is filtered with only visible light being reflected onto afiber receiver 32 for distribution to the fiberoptic lighting network.FIG. 2 is a front view rendering showing the primary mirror 30 and thesecondary mirror mount 33. The secondary mirror mount 33 blocks lessthan 5% of the sunlight reflected from the primary mirror 30. FIG. 3 isa rear view of the hybrid solar collector. Structural features of thesecondary mount 33 enable the mount to flex while maintaining thepreferred optical specifications as described with reference to FIG. 4below. The flexure in the mount 33 relieves stress points where themount 33 attaches to the primary mirror 30. FIG. 5 is a renderingshowing the secondary mirror 31 mounted to the secondary mount 33. Theprofile of the secondary mirror 31 can be parabolic or inverseelliptical shape, as dictated by the performance criteria for themirror. Multiple solar concentrators can be used as a mirror farm arrayconnected to a single sun tracking system.

Referring now to FIG. 4, the preferred optical specifications of theprimary mirror 30 and secondary mirror 31 are discussed. All positionalmeasurements are made from a primary mirror vertex 200 and a secondarymirror vertex 202. A fiber axis 204 is defined by the fiber receiver 32.The secondary mirror is centered on the fiber axis 204 and is adjustableplus or minus 10 mm. The primary mirror is centered on the fiber axis204 and is adjustable plus or minus 6.0 mm. A secondary mirror axis 206is parallel to the fiber axis 204 plus or minus 0.6 degrees. A primarymirror axis 208 is parallel to the fiber axis 204 plus or minus 0.25degrees. The secondary mirror 31 preferably has a 6.35+/−0.25 mmthickness, and the primary mirror 30 preferably has a 8.3+/−0.3 mmthickness. Distance 210 is preferably 190.0 mm, distance 212 ispreferably 1181.1 mm, distance 214 is preferably 358.0+/−2.0 mm, anddistance 216 is preferably 132.0+/−2.0 mm. The focus of the primarymirror 30 is preferably 419.1 mm as defined by the equation: “z=R²/1676.4”. Finally, the semi-major axis of the secondary mirror 31 ispreferably 209.68 mm, and the semi-minor axis of the secondary mirror 31is preferably 157.48 mm.

FIG. 6 shows the fiber receiver 32 mounted in the center core of theprimary mirror 30. FIG. 7 shows the fiber receiver 32 componentsincluding a mixing rod 40, preferably made of a quartz material, whichacts as heat dissipation means, and an optional filter 41 to rejectremaining IR energy not filtered by the secondary mirror 31. Fiber 43 isforcibly bonded to the mixing rod 40 inside the receiver housing 42 tominimize fresnel losses and associated thermal loading. Light emergingfrom the mixing rod 40 into the fiber 43 is uniformly distributed so asto maximize the amount of light that can be injected into the polymerfibers. A commercially available thermally compressed fiber bundle canbe used in the fiber circuit to minimize packing losses of multiplefibers. Also the focal spot on the mixing rod 40 can be smaller than itsdiameter so as to reduce the tracking accuracy needs of the system.

FIG. 8 renders an indirect lighting embodiment of hybrid lighting usinga fiber optic diffusing rod 81 in conjunction with an electric lightingsource such as a fluorescent fixture 82. FIG. 9 shows a recesseddown-lighting fixture 91 having an electric light source 92 and opticalfibers 93 feeding at least one solar lighting element 94 movablydisposed on the fixture 91. The electric light source 92 is selectedfrom the group consisting of incandescent, halogen, compact fluorescent,and high intensity discharge (HID) lighting. FIG. 10 shows a tracklighting fixture 101 having an electric light source 102 and opticalfibers 103 feeding at least one solar lighting element 104 movablydisposed on the fixture 101. The electric light source 102 is selectedfrom the group consisting of incandescent and halogen lighting.

FIG. 11 shows a hybrid light emitting diode (LED) luminaire 111 usingwhite light. Both the LED elements 112 and fiber optic solar lighting113 are point source, directional illuminators. The solar lightingimproves the LED luminaire 111 efficiency. Adaptive color matching ofsunlight may be feasible using hybrid LED luminaires.

For building applications, the most significant loss factor in the lightcollection and distribution system is the end-to-end attenuation inlarge-core optical fibers. This invention, as shown in FIG. 8, moreefficiently and cost-effectively transports sunlight through newpolymer-based large core optical fibers 120 or a thermally compressedpolymer-based fiber bundle 122 rather than glass fiber optic bundles. Acentrally located fiber distribution panel 124 can serve as a “plug andplay” source to feed multiple fixtures with sunlight. A new “hybrid”luminaire 126 spatially distributes both fiberoptic-delivered sunlightand electric light in a general lighting application and controls therelative intensity of each based on sunlight availability usingphotosensors and dimmable electronic ballasts. Thus, natural light iscollected at a central location and distributed to multiple luminaries.The hybrid luminaire 126 can be used with various electric light sourceincluding halogen, high intensity discharge, metal halide, high and lowpressure sodium, incandescent, light emitting diodes (LED), and othercommon electric lighting lamps. Lighting applications include direct,indirect, cove, spot, compact fluorescent, track, and perimeter pointsource. Fixtures can be laterally adjusted in product spotlightingapplications.

Another embodiment of the hybrid luminaire comprised a cylindricaldiffusing rod having a 2.54 cm diameter, 1.0 m long, optically clearcylinder with a polished lower hemicylinder and a diffuse upperhemicylinder. Light launched from a butt-coupled optical fiber, scattersfrom the diffuse upper surface of the cylinder and escapes through thepolished lower surface of the cylinder. To improve efficiency,upward-scattered light is redirected back toward the lower hemicylinderof the diffusing rod with a silver-coating on the upper hemicylinder.

Three diffusing rods, each placed mid-way and slightly above adjacentfluorescent lamps in a 4-tube PARAMAX Parabolic Troffer with 24-celllouvre baffle, were expected to produce a spatial intensity distributionwhich closely matched that of the four fluorescent tubes. However,initial modeling of the diffusing rod indicated that the intensity ofthe scattered light was too highly concentrated toward one end of therod, creating uneven illumination. In addition, a large portion of thelight entering the diffusing rod at small angles was not being scatteredat all and, instead, was merely being reflected from the planar end ofthe diffusing rod back into the butt-coupled optical fiber. To overcomethese deficiencies, a silver-coated concave mirror surface at the end ofthe rod was added to the diffusing rod model. This concave end-mirrorstrongly diverged low-angle incident light, hence improving the opticalefficiency of the diffusing rod while also improving the overalluniformity of the scattered light. To further improve the uniformity ofthe scattered light, a 40 cm strip along the center of the diffusingrod's top hemicylinder was modeled with a larger scattering fractionthan the outer ends to increase the amount of scattered light emittedfrom the center of the diffusing rod.

Simulations of the spatial intensity distribution resulting from thefluorescent lamps and/or the diffusing rods revealed only minordifferences between the two distributions, and only minor deviation fromthe fixture's original spatial intensity distribution. However, due toobstruction and scattering losses associated with the inclusion of thethree diffusing rods, the optical efficiency of the fixture wasdecreased from 64% to 53%. The diffusing rod itself was estimated to beonly 50% efficient at converting a fiber optic end-emitted source into acylindrical source. This efficiency was strongly dependent upon theintensity profile of the fiber optic end-emitted light and thecombination of scattering values used along the top surface of thediffusing rod.

The cylindrical diffusing rod was a 2.54 cm diameter, 1 m long, castacrylic rod, with high optical clarity and optically smooth outersurface. The rod was diamond-machined on one end to create a concavesurface with a radius of curvature of 4.0 cm, and polished on the otherend to create a planar optical surface suitable for butt-coupling to alarge-core optical fiber. The top hemicylinder of the rod wassandblasted to produce a uniform scattering surface and both the tophemicylinder and concave end-mirror were coated with aluminum. Due toconstruction limitations, the top surface did not exhibit a variablesurface scatter as originally modeled.

Preliminary testing of the cylindrical diffusing rod revealed adiscrepancy between the desired modeled surface scatter and the actualsurface scatter created by the sandblasting technique. Because opticalscattering is often difficult to accurately model in software, theresult was not entirely unexpected. The actual surface scatter createdby the sandblasting technique was much larger than modeled and created adiffusing rod with an uneven illumination. However, now given thecorrelation between the modeled scattering values and the actualscattering values, it is possible to re-simulate and re-design thecylindrical diffusing rod to emit a more uniform intensity distribution.Additional factors related to optical efficiency and construction costsare currently being evaluated. A luminaire design was sought that wouldprovide a simple means of seamlessly combining the light from thefluorescent and fiber optic sources.

Typically, the sunlight exiting the optical fibers produces a conicaldistribution pattern that is not compatible with the pattern produced byfluorescent lamps. To make the intensity distribution pattern morecompatible with that from the fluorescent tubes, it was necessary totransform the light from the fiber into a more cylindrical geometry.Various attempts were tried to construct nonimaging optical componentsto achieve this goal. Ultimately, the best results were obtained byusing a cylindrical, side-emitting diffusing rod developed by 3M (3MSide-Emitting Rod Part #: LF180EXN). Two versions of this optic wereused in initial tests: the S version, designed for single fiberillumination via one end, and the D version, intended for use with twoilluminating fibers. The best linear uniformity of the emitted light wasobtained by using the D version with the illuminating fiber at one endof the rod and a reflecting element at the other.

The grooves in the flat surface of the 3M side-emitting rod serve toreflect light out the opposite side of the rod. Ideally, all of thelight would be reflected out the side of the rod by the time the last ofthe rays reached the far end of the rod. In practice, however, asignificant portion of the light exits the end of the rod instead of theside. To further improve the efficiency of the side-emitting rod,various reflectors were attached to the end of the rod. Ultimately, aconcave spherical mirror (produced by aluminizing the curved side of aplano-convex lens) seemed to produce the best results. The mirror servedto reflect and diverge any coaxial light that was not scattered on aninitial pass through the rod. The rod was mounted within acustom-machined acrylic holder that allowed a large-core optical fiberto mate with one end of the rod.

In the initial design, two assembled rods were mounted within afour-tube fluorescent fixture. The two side-emitting rods were locatedon each side of the ballast cover, directly between the twocorresponding fluorescent tubes. The side-emitting rods were mounted sothat the light was projected toward the acrylic diffuser and out of thefixture. This dual-rod design was selected to provide good spatialdistribution match to the light from the fluorescent tubes.Unfortunately, the design required the use of a high-quality splitter(low-loss, 50:50 split) to divide the light from a single fiber into thetwo light tubes.

The hybrid luminaire was mounted and tested. Instead of using asplitter, two separate optical fibers sources were used. Thus, themeasured efficiency did not reflect the additional losses that would becontributed by the connection losses and inherent internal lossassociated with using a splitter.

The initial tests of the hybrid luminaire indicated that coupling lossesfrom the fiber to the side-emitting rod were high, leading to reducedefficiency. Design enhancements to the luminaire were added to stabilizethe position of the side-emitting rods and improve coupling efficiency.The enhanced version of the dual-rod design was tested to measure theimprovement in performance.

To further improve efficiency and lower the cost of the luminaire, theinstant invention used only one side-emitting rod. By using only oneside-emitting rod, the need for a splitter would be obviated,eliminating the connection losses into and out of the splitter as wellas the inherent loss within the splitter itself. In addition, the costof the splitter and the additional side-emitting rod would beeliminated. However, the use of a single side-emitting rod would requiretwo major modifications to the luminaire design. The rod would have tobe mounted in the center of the luminaire to maintain symmetry in theintensity distribution pattern, and it would have to be rotated 180° tobroaden the intensity distribution pattern by reflecting theside-emitted light from the rear surface of the fixture.

To enable the side-emitting rod to be centrally mounted, the standardballast and ballast cover were removed, making the central portion ofthe luminaire available for development. A compact(16.5-in.×1.25-in.×1-in.), four-bulb, dimmable ballast was obtained fromAdvance Transformer (Mark 7 IntelliVolt series, product number IZT-4S32)and installed on the rear of the luminaire housing.

A second feature of the invention was necessary to achieve an acceptableintensity distribution pattern from a single emitting rod. To achieve apattern of sufficient width, the direction of the rod would have to bereversed, directing the light onto the reflective housing of theluminaire and allowing the diffuse reflection to exit the acrylicdiffuser, rather than projecting the light directly onto the acrylicdiffuser. If the light from the single rod were projected directly ontothe acrylic diffuser, the intensity distribution pattern would beunacceptably narrow in comparison to that from the fluorescent lamps. Toimprove the efficiency and intensity distribution characteristics of thenew design, a diffuse reflective film was used in conjunction with theside-emitting rod. A “Light Enhancement Film” from 3M (Scotchcal3635-100) was placed on the luminaire housing in the area directlybehind the side-emitting rod. This film provided a more diffusereflection and higher reflectivity than the reflective paint in theluminaire (94% vs 90%).

An additional invention feature was added to the single-rod design tofurther enhance the optical efficiency. Previous designs had used areflector at the end of the side-emitting rod to direct the coaxiallight back through the rod. Though the intention was to force all of thelight to eventually be emitted out the side of the rod, some light wassuspected of traveling back up the source fiber where it could not beused for illumination. An improvement was made in the single-rod design.Rather than attaching a reflector to the end of the side-emitting rod, abundle of small optical fibers was attached to the end of the rod androuted back into the central portion of the luminaire. Coaxial lightthat was not emitted from the side-emitting rod would enter the bundleof fibers and be redirected into the luminaire where it would add to theside-emitted light from the rod. The fibers were simply routed aroundthe ends of the fluorescent tubes and back toward the center of theluminaire where the exiting light was scattered off of the 3M lightenhancement film. In future embodiments, the fibers could be arranged toachieve a more uniform contribution to the overall intensitydistribution.

The efficiency of the luminaires shows consistent improvement, with thesingle-rod luminaire providing almost 79% efficiency. This is verycomparable to the 81% efficiency of the fluorescent portion of theluminaire. The light distribution for the single-rod luminaire iscomparable to that of the fluorescent system as well, noting that thedual-rod designs placed a higher percentage of the incident light on thefloor of the illumination cell. The only undesirable feature of thesingle-rod luminaire is an uneven distribution of light between thedifferent walls of the illumination cell. In particular, the scatteringcharacteristics of the side-emitting rod in the inverted configurationtended to increase the light on one end-wall of the illumination cell.This is considered to be within the bounds of acceptable variation, butefforts will be made to further equalize the distribution from thisdesign.

A major step toward the realization of using fiber optic transportedsolar light for internal lighting purposes involves the development of ahybrid luminaire to seamlessly balance lamp and fiber optic transportedsolar illuminants. Fluctuations in the intensity of collected solarlight, due to changing cloud coverage or solar collector movement,requires rapid compensation by electric lamps to maintain a constantroom illumination. If the spatial intensity distribution of a hybridluminaire's electric lamp does not closely match the spatial intensitydistribution of the luminaire's fiber optic end-emitted solarilluminant, then the shift between artificial and solar lighting will benoticeable to the occupant and is highly undesirable.

To date, there are a wide variety of commerically-available daylightingsensors manufactured by a variety of vendors. These sensors range inprice from $50-$300 and come in a variety of optical packages suitableto various workspace environments (i.e. office spaces, conference rooms,atriums, etc.). Despite the variation in packaging, these sensors allwork on essentially the same basic principle. The sensor, which ismounted in the ceiling, contains a plastic lens that images light fromthe workplane onto a photodetector. The output from the photodetector isa measure of the combined sunlight and artificial lighting levels withina specified viewing angle (also called the sensor's “cone of response”)

From the photodetector's output (and the ballast voltage), the sunlightlevels versus artificial lighting levels can be calculated. Theseindirect measurements are used with a control algorithm (either aconstant set point or a sliding set point algorithm) to appropriatelyadjust the intensity of the fluorescent lighting.

When the sunlight and artificial lighting are identically distributedover a given area, current commercial sensors have been shown to performwell. However, when the spatial distribution of the sunlight andartificial lighting are quite different, which is typically the case inan office environment, the indirect calculation of sunlight levelsversus artificial lighting levels is inaccurate. Because of the highratio of uplighting to downlighting associated with sunlight enteringthrough a window, this indirect measurement often results in a sensorthat is overly sensitivity to sunlight. As a result, commerciallyavailable sensors overcompensate for sunlight, resulting in controlledlighting levels that can fall well below desired workplane illuminancelevels.

To improve the performance of daylight harvesting algorithms, a sensoris needed that allows for the independent measurement, as opposed to thecombined measurement, of sunlight and artificial light within acontrolled area.

Unlike commercial sensors, the daylight harvesting sensor in the instantinvention is capable of measuring sunlight and artificial lighting levelseparately. The daylighting sensor accomplishes this by exploiting thefrequency differences between sunlight and fluorescent lighting.Although undetectable to humans, the intensity of fluorescent lightingactually oscillates, or “flickers”, at a very high frequency (>10 KHzfor most dimmable ballasts). In contrast, sunlight does not flicker andis extremely constant over a short period of time (<1 sec). A high-speedphoto-detector is capable of measuring both signals simultaneously.

The magnitude of the photodetector's high-frequency component isproportional to the fluorescent lighting levels at the workplane. Themagnitude of the signal's constant, or DC, component is proportional tothe sunlight levels at the workplane.

Factoring in phase differences between nearby fluorescent fixtures,which can complicate the simple relationship, the following equationcomprises the harvesting sensor's control algorithm:

$\frac{{K_{s} \cdot V_{D\; C}} + {\left( {1 - K_{s}} \right) \cdot m_{p} \cdot V_{P\; 2P}} + {\left( {1 - K_{s}} \right) \cdot b_{p}}}{\left\lbrack \frac{{m_{p} \cdot V_{P\; 2P}} + b_{p}}{{m_{B} \cdot V_{Ballast}} + b_{B}} \right\rbrack} = {Constant}$

-   -   where:    -   m_(P), m_(B), b_(p), b_(B)=are determine during power-up.    -   V_(P2P)=Peak-to-Peak Amplitude of Oscillating Signal    -   V_(DC)=Average DC voltage of signal    -   V_(Ballast)=Voltage to Ballast Control Line    -   K_(s)=Calibration factor        This equation represents the basic control algorithm for        workspaces illuminated with sunlight and fluorescent lighting.        The ballast voltage (Vballast) is modified to keep the above        equation constant with increasing sunlight. Modifications can be        made to this control algorithm to accommodate unique lighting        environments where sunlight and fluorescent lighting are        supplemented with non-fluorescent artificial lighting.

The performance of a prototype daylight harvesting sensor was testedagainst leading commercial daylighting sensors. Comparative testsperformed in a typical 10′×10′ office environment, with a 24″×30″window, demonstrated the sensor's superior performance over commercialsensors. In sharp contrast to the commercial sensor, which exhibitedlarge fluctuations in room illumination throughout the day (maximumfluctuation=65%), the harvesting daylighting sensor exhibited only minorillumination fluctuations (maximum fluctuation<5%).

While there has been shown and described what are at present consideredthe preferred embodiments of the invention, it will be obvious to thoseskilled in the art that various changes and modifications can be madetherein without departing from the scope.

1. A hybrid solar energy distribution system comprising: at least onefiber receiver for receiving visible light further comprising; areceiver housing, a mixing rod removably disposed in said receiverhousing, a fiber at least partially disposed in said housing and engagedwith said mixing rod, said fiber further transmitting visible light to alight distribution system further comprising; at least one fiberdistribution panel; at least one hybrid luminaire; and a means forcontrolling at least one of said hybrid luminaire and said lightdistribution system.
 2. The hybrid solar energy distribution system ofclaim 1 wherein said hybrid luminaire comprises at least one of thelighting types selected from the group consisting of direct, indirect,cove, spot, compact fluorescent, track, recessed down-lighting, LED,sunlight, and perimeter point source lighting.
 3. The hybrid solarenergy distribution system of claim 1 wherein said fiber furthercomprises a thermally compressed fiber bundle.
 4. A hybrid collectorcomprising; a primary mirror for producing reflected full spectrum solarradiation, a secondary mirror supported in position for receiving saidreflected full spectrum solar radiation and further filtering said fullspectrum solar radiation into visible light that is reflected onto afiber receiver, said fiber receiver further comprising; a receiverhousing, a mixing rod removably disposed in said receiver housing, afiber at least partially disposed in said housing and engaged with saidmixing rod, said fiber further transmitting visible light to a lightdistribution system further comprising; at least one fiber distributionpanel; at least one hybrid luminaire; and a means for controlling atleast one of said hybrid luminaire and said light distribution system.5. The hybrid collector of claim 4 wherein said secondary mirror issupported by a secondary mount further comprising; a non-rigid structurethat blocks less than 5% of said reflected full spectrum solar radiationand maintains predetermined optical distances.
 6. The hybrid collectorof claim 4 wherein said fiber further comprises a thermally compressedfiber bundle.
 7. The hybrid collector of claim 4 wherein multiplecollectors are positioned in a mirror farm array connected to a singlesun tracking system.
 8. The hybrid collector of claim 4 wherein saidprimary mirror is segmented into multiple sections.
 9. The hybridcollector of claim 4 wherein said secondary mirror is segmented intomultiple sections.
 10. The hybrid collector of claim 4 wherein saidprimary mirror and secondary mirror are segmented into multiplesections.